Head of a jellyfish (medicine)

Against the background of enlarged abdomen due to ascites , enlarged convoluted saphenous veins can be traced, forming the “jellyfish head”

The head of the jellyfish ( lat. Caput medusae ) is the name given to the enlarged, crimped saphenous veins on the anterior abdominal wall, which has the meaning of a roundabout outflow of venous blood from the portal vein system ( vena portae ). This name is given because in such cases the veins around the navel , expanding, resemble the image of the head of the mythological Medusa - the most famous of the three Gorgon sisters, a monster with a female face, with writhing snakes instead of hair.

Expansion of the venous blood vessels in the anterior abdominal wall develops due to the redistribution of venous blood into the bypass portocaval and caval anastomoses , which have a value of a circumferential outflow path from the portal vein system when obstacles arise to its normal passage in the portal vein itself. Such violations of the outflow of venous blood through the portal vein most often develop with pathologies that impede the passage of blood through the liver: with cirrhosis of the liver , including alcoholic cirrhosis of the liver, as well as cancer of the liver.

Normally, the venous blood from all unpaired abdominal organs ( stomach , small and large intestine , spleen and pancreas ) flows into the portal vein, with the exception of the liver and the lower third of the rectum . From these organs, venous blood enters the liver through the portal vein, and from it through the hepatic veins into the inferior vena cava . In the venous system, additional pathways of blood outflow, in addition to the main deep veins and their tributaries, are also superficial or saphenous veins , as well as venous plexuses that are widely developed in humans. The most important in clinical practice are intersystem venous anastomoses, through which the systems of the upper and lower hollow and portal veins are connected. As a result, porto-caval, caval-caval, and also cavo-cavaportal anastomoses are formed. All of them have the value of the collateral (detour) path of blood outflow bypassing the main veins. Porto-caval anastomoses are normally poorly developed in humans, but when the blood flow is disturbed through the portal vein system, they expand significantly. In this case, they provide the process of "dumping" blood to bypass the liver from the portal vein system into the system of the superior and inferior vena cava.